import {
  document,
	window,
	HTMLCanvasElement,
	requestAnimationFrame,
	cancelAnimationFrame,
core,
	Event,
  Event0
} from "dhtml-weixin"
import * as THREE from './three/Three';

import Stats from 'three/addons/libs/stats.module.js';

import { GUI } from 'three/addons/libs/lil-gui.module.min.js';

var requestId
Page({
  onShareAppMessage(){
    return getApp().onShare()
  },
  onShareTimeline(){
     return {title:"ThreeX 2.0"}
  },
	onUnload() {
		cancelAnimationFrame(requestId, this.canvas)
		this.worker && this.worker.terminate()
if(this.canvas) this.canvas = null
		setTimeout(() => {
			if (this.renderer instanceof THREE.WebGLRenderer) {
				this.renderer.dispose()
				this.renderer.forceContextLoss()
				this.renderer.context = null
				this.renderer.domElement = null
				this.renderer = null
			}
		}, 0)
	},
  webgl_touch(e){
		const web_e = (window.platform=="devtools"?Event:Event0).fix(e)
		this.canvas.dispatchEvent(web_e)
  },
  onLoad() {
		document.createElementAsync("canvas", "webgl2").then(canvas => {
      this.canvas = canvas
      this.body_load(canvas).then()
    })
  },
  async body_load(canvas3d) {	
  let camera, scene, renderer, stats, parameters;
  let mouseX = 0, mouseY = 0;

  let windowHalfX = window.innerWidth / 2;
  let windowHalfY = window.innerHeight / 2;

  const materials = [];

  init();
  animate();

  function init() {

    camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 2000 );
    camera.position.z = 1000;

    scene = new THREE.Scene();
    scene.fog = new THREE.FogExp2( 0x000000, 0.0008 );

    const geometry = new THREE.BufferGeometry();
    const vertices = [];

    const textureLoader = new THREE.TextureLoader();

    const assignSRGB = ( texture ) => {

      texture.colorSpace = THREE.SRGBColorSpace;

    };

    const sprite1 = textureLoader.load( 'textures/sprites/snowflake1.png', assignSRGB );
    const sprite2 = textureLoader.load( 'textures/sprites/snowflake2.png', assignSRGB );
    const sprite3 = textureLoader.load( 'textures/sprites/snowflake3.png', assignSRGB );
    const sprite4 = textureLoader.load( 'textures/sprites/snowflake4.png', assignSRGB );
    const sprite5 = textureLoader.load( 'textures/sprites/snowflake5.png', assignSRGB );

    for ( let i = 0; i < 10000; i ++ ) {

      const x = Math.random() * 2000 - 1000;
      const y = Math.random() * 2000 - 1000;
      const z = Math.random() * 2000 - 1000;

      vertices.push( x, y, z );

    }

    geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( vertices, 3 ) );

    parameters = [
      [[ 1.0, 0.2, 0.5 ], sprite2, 20 ],
      [[ 0.95, 0.1, 0.5 ], sprite3, 15 ],
      [[ 0.90, 0.05, 0.5 ], sprite1, 10 ],
      [[ 0.85, 0, 0.5 ], sprite5, 8 ],
      [[ 0.80, 0, 0.5 ], sprite4, 5 ]
    ];

    for ( let i = 0; i < parameters.length; i ++ ) {

      const color = parameters[ i ][ 0 ];
      const sprite = parameters[ i ][ 1 ];
      const size = parameters[ i ][ 2 ];

      materials[ i ] = new THREE.PointsMaterial( { size: size, map: sprite, blending: THREE.AdditiveBlending, depthTest: false, transparent: true } );
      materials[ i ].color.setHSL( color[ 0 ], color[ 1 ], color[ 2 ], THREE.SRGBColorSpace );

      const particles = new THREE.Points( geometry, materials[ i ] );

      particles.rotation.x = Math.random() * 6;
      particles.rotation.y = Math.random() * 6;
      particles.rotation.z = Math.random() * 6;

      scene.add( particles );

    }

    //

    renderer = new THREE.WebGLRenderer();
    renderer.setPixelRatio( window.devicePixelRatio );
    renderer.setSize( window.innerWidth, window.innerHeight );
    document.body.appendChild( renderer.domElement );

    //

    stats = new Stats();
    document.body.appendChild( stats.dom );

    //

    const gui = new GUI();

    const params = {
      texture: true
    };

    gui.add( params, 'texture' ).onChange( function ( value ) {

      for ( let i = 0; i < materials.length; i ++ ) {

        materials[ i ].map = ( value === true ) ? parameters[ i ][ 1 ] : null;
        materials[ i ].needsUpdate = true;

      }

    } );

    gui.open();

    document.body.style.touchAction = 'none';
    document.body.addEventListener( 'pointermove', onPointerMove );

    //

    window.addEventListener( 'resize', onWindowResize );

  }

  function onWindowResize() {

    windowHalfX = window.innerWidth / 2;
    windowHalfY = window.innerHeight / 2;

    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();

    renderer.setSize( window.innerWidth, window.innerHeight );

  }

  function onPointerMove( event ) {

    if ( event.isPrimary === false ) return;

    mouseX = event.clientX - windowHalfX;
    mouseY = event.clientY - windowHalfY;

  }

  //

  function animate() {

    requestId = requestAnimationFrame( animate );

    render();
    stats.update();

  }

  function render() {

    const time = Date.now() * 0.00005;

    camera.position.x += ( mouseX - camera.position.x ) * 0.05;
    camera.position.y += ( - mouseY - camera.position.y ) * 0.05;

    camera.lookAt( scene.position );

    for ( let i = 0; i < scene.children.length; i ++ ) {

      const object = scene.children[ i ];

      if ( object instanceof THREE.Points ) {

        object.rotation.y = time * ( i < 4 ? i + 1 : - ( i + 1 ) );

      }

    }

    for ( let i = 0; i < materials.length; i ++ ) {

      const color = parameters[ i ][ 0 ];

      const h = ( 360 * ( color[ 0 ] + time ) % 360 ) / 360;
      materials[ i ].color.setHSL( h, color[ 1 ], color[ 2 ], THREE.SRGBColorSpace );

    }

    renderer.render( scene, camera );

  }
  }
})